1. Field of the Invention
This invention relates generally to sunshades, rain-shields, and especially to umbrellas.
In particular, this invention concerns a disposable umbrella having a friction-lock arrangement for opening and closing a canopy.
2. Background of the Invention
Umbrellas conventionally employ a canopy supported by an elongated handle. The canopy is typically maintained in an open position by ribs that are held in place by a spring latch mechanism as typically illustrated in U.S. Pat. Nos. 1,484,367, 1,574,538 and 1,697,520.
Another latch mechanism, in the form of a bayonet slot and pin is shown in U.S. Pat. No. 1,858,960. A further latch device, as disclosed in U.S. Pat. No. 2,567,284, utilizes a spring collar mechanism.
The opening and closing mechanisms of these umbrellas contribute to the manufacturing cost in terms of both materials and labor and generally would not be economically justifiable for a limited-use umbrella.
Although U.S. Pat. No. 2,747,592 shows use of frictional engagement to hold an umbrella open, the telescopic tube arrangement of that device does not lend itself to a simplified assembly having a minimum of components as in the present invention.